if we realize how plainly and directly Prince’s appropriations damaged Cariou’s opportunities to economically benefit from his own work, the outcome (if not all of the reasoning) of this new case is obviously correct.Appropriation art, like most art, only exists in the guise of "art for art's sake." Whenever art enters a market, is reproduced, or hangs in a gallery, it enters a world of commerce that has tangible impact on a great many people, including other artists. Courts have signaled that they are far from hostile to the idea of appropriation art in general (see Blanch v. Koons) and in Gordon v. McGinley the judge memorably stated his unwillingness to find copyright infringement in a recent case. As far as I can tell, appropriation art per se isn't under siege; rather, courts are holding artists responsible for actions that might adversely affect the well-being of other artists - and I'm ok with that.
See a summary of responses to the case.